scholarly journals The Improvement of the Quality of Construction Foam and Non-Autoclave Foam Concrete on Its Basis through the Introduction of Nanosize Additives

Author(s):  
Anastasia Sychova ◽  
Larisa Svatovskaya ◽  
Maxim Sychov
Keyword(s):  
Author(s):  
Sergey Shcherbin ◽  
Pavel Gorbach ◽  
Andrey Savenkov

Author(s):  
Al'bina Baranova ◽  
Ol'ga Yazina ◽  
Anna Bobrova ◽  
Kristina Rudyh

The article presents the coefficients of the constructive quality of fine-grained concrete and structural foam concrete with different percentages of micro-silica in the mixture.


Author(s):  
Д. Нецвет ◽  
Dar'ya Necvet ◽  
В. Нелюбова ◽  
Viktoriya Nelyubova ◽  
В. Строкова ◽  
...  

The possibility of increasing efficiency of non-autoclaved foam concrete due to the use of complex binder with mineral components of different composition has been theoretically substantiated and experimentally confirmed. The opportunity to use the anhydrous calcium sulphate as a modifying component of the mixture is proved, which accelerates the setting of the mixture. This allows to "fix" the structure of the aerated concrete mixture with minimal shrinkage deformations. It is shown that the combined use of anhydrite and a mineral additive in the form of a quartz suspension obtained by grinding sand in an aqueous medium leads to a liquefaction of the mixture, which is associated with a decrease in the share of the structure-forming component. From a technological point of view, this will allow obtaining materials with a rational pore structure by optimizing the processes of pores formation. Composite binder with mineral additives is characterized by increased strength with a reduced share of clinker component in comparison with cement. In result, the minimization of shrinkable deformations and improvement of the quality of cellular concrete are ensured


2020 ◽  
Vol 2020 (2) ◽  
pp. 69-76
Author(s):  
Vasyl Iliv ◽  
◽  
Khrystyna-Dzvenyslava Iliv ◽  

Production of foam concrete products and monolithic concreting from them requires foaming agents that have the properties of the obtained foam with a sufficient value of its criteria (multiplicity of foaming, stability of foam for a certain period of time); its compatibility with Portland cement and its hydration products; with hydrated lime, etc. Insufficient properties of the foam can be compensated by the introduction of corrective and stabilizing additives. Although the studied foaming agents are not always environmentally friendly products, but their low concentration in foam concrete creates a precedent for their indispensability in the production process. The investigated foaming agents practically do not differ in multiplicity and stability at their use in 1% solution. The best technological properties are inherent in the foam obtained from the foaming agent of the PEAS brand. The introduction of the additive partially increases the multiplicity and stability of the foam. In addition, it acts as an accelerator of the set of strength on the hardening of foam concrete, which increases the reversibility of metal molds and accelerates the load of the monolith. It was found that foam concrete compositions that do not contain additives are mainly prone to delamination and shrinkage, so in the manufacture of samples from them, much attention was paid to the quality of the obtained samples. This indicates that the additive is not only a foam stabilizer, it also stabilizes the foam concrete mixtures obtained on their basis.


Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


Author(s):  
L. D. Jackel

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.


Author(s):  
G. Lehmpfuhl

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.


Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.


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